A film-like substrate (hereinafter, merely referred to as a “substrate”) such as a flexible substrate is relatively thin and easily warped. Accordingly, there have been proposed numerous techniques for correcting the warpage of a substrate at a position where an operation such as the mounting of components is performed on the substrate, i.e. at a working position. For example, in the disclosure disclosed in JP2004-296632A, after a substrate is placed on a lower supporting surface of a lower supporting member, a pressing member is lowered and pressed into surface contact with the substrate from above to press the substrate against the lower supporting surface. In this way, a warpage of the substrate is corrected. The substrate is vacuum-sucked to the lower supporting surface by the operation of a vacuum suction unit in this state.